The present invention relates generally to lithographic exposure equipment, and more particularly, to a photolithography system and method, such as can be used in the manufacture of semiconductor integrated circuit devices.
In conventional analog photolithography systems, the photographic equipment requires a mask for printing an image onto a subject. The subject may include, for example, a photo resist coated semiconductor substrate for manufacture of integrated circuits, metal substrate for etched lead frame manufacture, conductive plate for printed circuit board manufacture, or the like. A patterned mask or photomask may include, for example, a plurality of lines or structures. During a photolithographic exposure, the subject must be aligned to the mask very accurately using some form of mechanical control and sophisticated alignment mechanism.
U.S. Pat. No. 5,691,541, which is hereby incorporated by reference, describes a digital, reticle-free photolithography system. The digital system employs a pulsed or strobed excimer laser to reflect light off a pixel panel (e.g., a programmable digital mirror device, or xe2x80x9cDMDxe2x80x9d) for projecting an image (e.g., a line or pattern) onto a subject (e.g., a wafer, printed circuit board, textile, flexible member). The subject is mounted on a stage that is moves during the sequence of pulses.
The above-described digital photolithography system projects a pixel-mask pattern onto a subject such as a wafer, printed circuit board, or other medium. The component image consists of a plurality of pixel elements, corresponding to a pixel pattern provided to the pixel panel. As a result, light can be projected onto or through the pixel panel to expose the plurality of pixel elements on the subject, and the pixel elements can be moved and altered, according to the pixel-mask pattern, to create contiguous images on the subject.
Certain improvements are desired for digital photolithograph systems, such as the ones described above. For one, it is desirable to accommodate a desired change in the scale of the images being exposed. For example, if the subject were a textile, the image may need to expand and/or contract to accommodate the flexibility in the textile. In another example, it may be desirable to scale the image for other reasons.
A technical advance is provided by a novel method and system for scaling a pixel element on a subject. In one embodiment, the subject is positioned in a first plane and the method comprises providing a pixel panel to generate the pixel element, where the pixel panel is positioned in a second plane substantially parallel to the first plane. A first scan rate is determined, and an original focal point of the pixel element on the subject is determined. A scaled focal point is calculated for the pixel element on the subject, where the scaled focal point includes a first coordinate in a first dimension and a second coordinate in a second dimension. The pixel panel is rotated relative to the subject to position the pixel element at the first coordinate in rotated relative to the subject to position the pixel element at the first coordinate in the first dimension of the scaled focal point, and the first scan rate is altered to a second scan rate to position the pixel element at the second coordinate in the second dimension of the scaled focal point.